Have you tried using solid invisible blocks to create a invisible barrier around each track? You can then set up custom movement or 8 directional, or even bullet. Car movement might be what you want for a train game though
[QUOTE=RenatoB] I did some experiments with the 8-directions behavior and works too (I wonder why use the bullet instead of 8-directions). The problem is that the player is not stuck to the rail and does not change direction smoothly in perpendicular movements. If I move the playe horizontally and pressed the UP / DOWN in the middle of the line, the sprite loses the path reference and doesn't move anymore.
Please some more ideas and suggestions.